The attenuation material belongs to the highest M1 Emission-classification for building materials in Finland and is part of Classification of Indoor Climate 2000.Cleaning: by vacuum-cleaner or dry cleaning.

Silencers are in air- tightness class C.

All acoustical measurements and test methods have been done by Oy Lindab Ab own Labo along EN-standard ISO 7235:2003 -"Acoustics-Measurement procedures for ducted silencers"- and by VTT, the Technical Research Centre of Finland.